[MW:15822] Query for correct interpretation of Clause No.QW-407.2 of ASME Section IX

Dear Experts,

Please refer trail official interpretation of ASME Section IX.
Interpretation: IX-04-15

Subject:  QW-407.2, Base Metal Thickness Qualification and QW-407.2, PWHT Temperature and Time Range
Date Issued:    December 22, 2004
File No:    04-1595

Question (1):  Will a procedure qualification test coupon on 1.5 in. thick P-No. 1, Gr. 2 material and post weld heat treated at 1100 deg. F. for 1.5 hours with supplementary essential variable requirements met, support a WPS with supplementary essential variable requirements for production welding on 8 in. thick P-No. 1, Gr. 2 material that is PWHT at 1100 deg. F. for 3.5 hours?

Reply (1):  No.

Question (2):  Based on the conditions stated in Question 1, could the PWHT time on the 8 in. thick weldment be increased to 4 hours and 10 minutes at 1100 deg. F. and still be in compliance with Code requirements? 

Reply (2):  No.

As per my opinion

Answer as 'NO' is correct because requirement of at least 80% soaking time on test coupon is not meeting in both the cases.

Case-1 :  Soaking time on test coupon as 1.5 Hr is much less than 80% of 3.5 Hr soaking time given to production weld

Case-2 :  Soaking time on test coupon as 1.5 Hr is much less than 80% of 4.0 Hr & 10 Min. soaking time given to production weld

I have also seen previous expert replies for same subject as mentioned below

Reply of a

 

Because the supplementary essential variables must be met, the proposed WPS is not allowed - i.e. in QW-407.2 there is a maximum limit on time at temperature.  Specifically, "The procedure qualification test coupon . . . at least 80% of the aggregate time at temperature."

Thus the maximum time (Tmax) at temperature is :  (Tqual/Tmax) X 100 = 80

                                                      Or     Tmax = Tqual X ( 100/80) =  1.5 hr X (5/4) = 1.875 hours

So the PQR does not have a long enough hold time to support the proposed WPS's 3.5 hour hold time.

John A. Henning
Senior Welding & Materials Engineer


Please let me know out of following two interpretations, which interpretation is correct ?

1) QW-407.2 (including at least 80% of the aggregate times at temperature(s) ) is mean to specify minimum 80% of total aggregate time at temperatures for PWHT for established PQR

OR

2) QW-407.2 is mean to specify Maximum 1.25 time of total aggregate time at temperatures for PWHT for established PQR.

Kindly clarify.

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